1. Field of the Disclosure
This invention relates to connectors to electrically couple two or more components of a system. More particularly, there is disclosed a waterproof connector useful in a runway lighting system.
2. Description of the Related Art
Airport ground lighting systems are networks of lights and circuits that help guide aircraft in take-off, landing and taxiing along the runways and taxiways of an airfield. They play a vital role in keeping air travel safe. The luminous portion of the system consists of elevated lights and lighted signs at the side of runways and taxiways and inset lights which are embedded in the airport surfaces. A commercial airport in a large metropolitan area will have several hundred to several thousand lights of various types installed around the facility.
In a typical runway lighting system, an underground cable provides electrical power in series to a plurality of lighting fixtures. To prevent the failure of a single lighting fixture from causing the entire plurality of lighting fixtures to go out, an isolation transformer is disposed between the power source cable and the lighting fixture. The leads and connectors of this transformer are integrally molded into the transformer. A set of field-installed electrical connectors (typically one socket and one plug) is used to electrically connect the isolation transformer primary coil to the airport power circuit. As this connection is subsurface, it must be waterproof and impervious to other liquids commonly found in a runway environment such as jet fuel and deicing solution.
When a lighting fixture is to be added or replaced, the electrical connection needs to be made waterproof. Installation of a primary connector kit does not always yield a waterproof connection. Therefore, of common present use is a heat shrink kit. A plastic film that contracts when exposed to moderate heat is wrapped around the connection and then exposed to a hot air gun, or similar heat source, to then shrink about the connection forming a waterproof casing. However, this is a very time-consuming process that requires additional equipment and as a runway is typically out of service when lighting fixtures are being replaced, any delay in the installation of the lighting fixtures affects the profitability of the airport. In addition, the waterproof properties of a heat shrink casing are inconsistent and affected by the skill of the installer. Also, as the polymer shrinkage is nonreversible, the entire connection must be destroyed and replaced when testing a circuit and frequently, during the process to remove the heat shrink, the isolation transformer primary connectors are damaged and often the isolation transformer must be replaced.
A runway lighting system having a light fixture with a luminous portion slightly raised above the surface of a runway and an electric cable extending downward to a power source is disclosed in U.S. Pat. No. 6,113,245 to Reinert, Sr.
U.S. Pat. No. 5,868,584 to Cook, et al. discloses a pin-to-socket connector where each component has a retractable sleeve that can be stretched over the other retractable sleeve to form a waterproof, insulated interference fit. Both U.S. Pat. Nos. 5,868,584 and 6,113,245 are incorporated by reference in their entireties herein.
There remains, therefore, a need for a waterproof connector for a runway lighting system that is quick to assemble, easy to assemble and reusable.